1. Field of the Invention
This invention relates to a hub mechanism suitable for the self-propelling type light vehicle, particularly, to the pedal-propelled type wheelchair and conveyor cart.
2. Description of the Prior Art
The wheelchair for the physically handicapped or the sick has been designed on the presumption that it is used solely by the person disabled in leg, and intended to be capable of moving when wheeled by the attendant on the user or when the main wheels thereof are turned by arms of the user him(her)self. Conventional wheelchairs, therefor, require no action of the user's leg even when used by the person whose legs remain sound to some degree, and deprive the user of opportunities of training to restore the function of legs thereof, thereby resulting in a cause to weaken user's legs further.
The physically handicapped and the sick using the wheelchair are not always sound in arm and, rather, not a few of them desire to use legs thereof remaining sound for driving the wheelchair.
The provision of a propelling mechanism employing pedals for the wheelchair may satisfy such desire as above, however, rotary type pedals generally used for the bicycle are not suitable for the disabled in leg and inferior to lever type ones alternately trodden right and left. Further, an improved wheelchair must be movable in not only forward but also backward direction and, at need, also movable when wheeled by the attendant or when the user rotates the main wheels thereof similarly to the conventional wheelchairs.
Some of light vehicles as conveyor carts widely used in small scale factories for conveying loads are of automatic propelling type equipped with a motor driven with the battery, however, followed by such problems as high cost and heavy weight. A light vehicle for the abovesaid use, if fabricated into pedal-driven type, may be inexpensive and light in weight but must be movable in the forward and backward directions and when subjected to wheeling by man power.
An ordinary type pedal-propelling mechanism widely used for the bicycle is not suitable for the above purposes because of the rotary type of pedal and simple function thereof adaptable to the forward movement only. None of mechanisms suitable for the above purposes in practical use have not yet been found.